CN110697595A

CN110697595A - Truss arm and crane

Info

Publication number: CN110697595A
Application number: CN201911131927.8A
Authority: CN
Inventors: 秦绪起; 郭晓晨; 刘涛
Original assignee: Zhejiang Sany Equipment Co Ltd
Current assignee: Zhejiang Sany Equipment Co Ltd
Priority date: 2019-11-19
Filing date: 2019-11-19
Publication date: 2020-01-17

Abstract

The truss arm and hoist that this embodiment provided relate to the hoist field. The problem that the hoisting capacity of the existing truss arm is limited is solved. The truss arm comprises a first arm support, a first reducing joint and a second arm support which are sequentially arranged along a preset linear direction, wherein the cross sectional area of the second arm support is smaller than that of the first arm support and larger than that of the first connecting arm support and that of the second connecting arm support; the first arm support comprises at least two sub-arm supports arranged side by side. The crane includes a truss arm. Compared with the situation that only one sub-arm support is arranged, the overall width of the truss arm can be increased by arranging the at least two sub-arm supports, so that the lateral load resistance of the arm support can be improved; the second arm support is arranged, so that the width from the first arm support to the end part of the truss arm is gradually reduced, the influence of the sudden change of the width on the overall strength of the truss arm is avoided, the strength of the truss arm and the lateral load resistance are improved when the width of the truss arm is increased, and the overall hoisting capacity of the truss arm is effectively improved.

Description

Truss arm and crane

Technical Field

The invention relates to a crane, in particular to a truss arm and a crane.

Background

A crawler crane with a truss arm is usually formed by connecting a plurality of truss arms in a hinged manner to form a boom assembly with a certain length. And (4) transporting the truss type arm support component, the mast component, the arm head component and the like to a hoisting site, and assembling the truss type arm support component, the mast component, the arm head component and the like through hinging. In the working state, the truss arm can be arranged on the rotary table of the crane in a manner of being hinged around the horizontal shaft, so that the truss arm can be lifted or dropped in a vertical plane.

The truss type boom of a crane is usually kept in strength, rigidity by guy wires or tie plates, and when the truss type boom lifts a large load, the limitation on the lifting capacity is usually not the capability of the boom to resist deflection in the vertical lifting plane, but the lateral deformation in the horizontal plane, i.e. the capability to resist lateral loads.

The existing truss arm has the problem of insufficient lateral load resistance.

Disclosure of Invention

Objects of the invention include, for example, providing a truss arm that improves upon the problem of limited capacity of existing truss arms.

The invention also aims to provide a crane, which can solve the problem that the hoisting capacity of the existing truss arm is limited.

Embodiments of the invention may be implemented as follows:

the truss arm provided by the embodiment of the invention is used for being connected between a first connecting arm frame and a second connecting arm frame, the first connecting arm frame is used for being directly connected with an arm head part, and the second connecting arm frame is used for being directly connected with a rotary table of a crane, and the truss arm comprises: the first arm support, the first reducing joint and the second arm support are sequentially arranged along a preset linear direction, and the cross sectional area of the second arm support is smaller than that of the first arm support and larger than that of the first connecting arm support and that of the second connecting arm support; the first arm support comprises at least two sub-arm supports which are arranged side by side, the first variable diameter section is connected with the same end of the at least two sub-arm supports, and one end, far away from the first arm support, of the first variable diameter section is connected with the second arm support.

In addition, the truss arm provided by the embodiment of the invention can also have the following additional technical characteristics:

optionally: the truss arm further comprises a third reducer section;

the third variable diameter section is connected with the same ends of the at least two sub-arm supports, the third variable diameter section and the first variable diameter section are respectively positioned at two opposite ends of the first arm support, and one end, far away from the first arm support, of the third variable diameter section is used for connection of a second connecting arm support.

Optionally: the truss arm further comprises a second reducer section;

one end of the second arm support, which is far away from the first reducing joint, is connected with the second reducing joint.

Optionally: one end, far away from the second arm support, of the second variable diameter section is used for being connected with the first connecting arm support, and the first arm support, the first variable diameter section, the second arm support, the second variable diameter section and the first connecting arm support are sequentially connected along a preset straight line.

Optionally: the first arm support, the third variable diameter section and the second connecting arm support are sequentially connected along a preset straight line.

Optionally: the length of the first variable-diameter section and the length of the third variable-diameter section are both smaller than the length of the second variable-diameter section along the length direction of the truss arm.

Optionally: the number of the sub-arm supports is two, the two sub-arm supports are arranged in a fitting and parallel mode and are provided with gaps, and the width of each gap is larger than zero and smaller than that of each single sub-arm support.

Optionally: the cross-sectional area of the sub-arm frame is the same as that of the first connecting arm frame.

Optionally: the second arm support and the second variable diameter section are both strip-shaped frame structures.

The embodiment of the invention also provides the crane, and the crane comprises the truss arm.

The beneficial effects of the truss arm and the crane of the embodiment of the invention include, for example:

compared with the mode that only one sub-arm support is arranged, the truss arm can increase the whole width of the truss arm, so that the lateral load resistance of the arm support can be improved; the second arm support is arranged, so that the width from the first arm support to the end part of the truss arm is gradually reduced, the influence of the sudden change of the width on the overall strength and rigidity of the truss arm is avoided, the strength and rigidity of the truss arm and the lateral load resistance can be improved when the width of the truss arm is increased, and the overall hoisting capacity of the truss arm is effectively improved.

The crane comprises the truss arm, and can solve the problem that the lifting and carrying capacity of the conventional truss arm is limited.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a schematic structural diagram of a first view of a truss arm according to an embodiment of the invention;

fig. 2 is a schematic structural diagram of a first reducer section according to an embodiment of the present invention;

fig. 3 is a partial structural schematic view of a truss arm provided in an embodiment of the invention;

FIG. 4 is a schematic diagram of the dimensional relationships between components provided by an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of an arm head assembly according to an embodiment of the present invention;

fig. 6 is a structural diagram of a second perspective of a truss arm according to an embodiment of the invention.

Icon: 10-an arm head part; 20-a first connecting arm support; 21-a second connecting arm support; 100-truss arms; 110-a first reducer section; 120-a second reducer section; 130-a third reducer section; 140-a first boom; 141-sub arm frame; 150-a second arm support; 200-pin shaft.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. indicate an orientation or a positional relationship based on that shown in the drawings or that the product of the present invention is used as it is, this is only for convenience of description and simplification of the description, and it does not indicate or imply that the device or the element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention.

Furthermore, the appearances of the terms "first," "second," and the like, if any, are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

It should be noted that the features of the embodiments of the present invention may be combined with each other without conflict.

When the arm support is suspended in a vertical plane, the arm support is subjected to axial pressure along the length direction of the truss arm, and the axial pressure can cause lateral buckling of the arm support, which is one source of lateral load of the arm support. In addition, lateral forces due to wind forces, ground unevenness, etc. are another source of boom side loads. And increasing the size of the cross-sectional area, particularly increasing the size of the boom in the width direction, namely increasing the width of the cross-sectional area, can effectively improve the lateral load resistance of the boom, namely improving the lateral load resistance of the boom, thereby improving the lifting capacity of the boom. However, the way of increasing the width of the truss arm is not proper, and the side load resistance of the truss arm is still insufficient, and the truss arm and the crane provided by the embodiment can improve the technical problem.

Referring to fig. 1, a crane (not shown) according to an embodiment of the present invention includes a truss arm 100. The crane further comprises an arm head part 10, a crane rotary table (not shown in the figure), a first connecting arm frame 20 and a second connecting arm frame 21, wherein one end of the truss arm 100 is connected with the arm head part 10 through the first connecting arm frame 20, and the other end of the truss arm 100 is connected with the crane rotary table through the second connecting arm frame 21.

Referring to fig. 1, in the present embodiment, the truss arm 100 is configured to be connected between a first connecting arm frame 20 and a second connecting arm frame 21, the first connecting arm frame 20 is configured to be directly connected to the arm head part 10, the second connecting arm frame 21 is configured to be directly connected to a turntable of a crane, and the truss arm 100 includes: the first arm support 140, the first reducer section 110 and the second arm support 150 are sequentially arranged along a preset linear direction (direction a in the drawing), and the cross sectional area of the second arm support 150 is smaller than that of the first arm support 140 and larger than that of the first connecting arm support 20 and that of the second connecting arm support 21; the first arm support 140 includes at least two sub-arm supports 141, the at least two sub-arm supports 141 are arranged side by side, the first reducing joint 110 is connected to the same end of the at least two sub-arm supports 141, and the end of the first reducing joint 110 away from the first arm support 140 is connected to the second arm support 150.

It should be noted that: the "cross-sectional area" herein refers to a cross-sectional area perpendicular to the direction of a predetermined straight line. In the embodiment, the cross section area is large, and the structural strength and the rigidity are large; the cross-sectional areas are the same, namely the rectangular areas surrounded by the axes of the four steel pipes which are arranged in the direction vertical to the preset straight line are correspondingly the same. The arm supports with the same cross-sectional area can be directly connected through the joint and the pin shaft without transition through a variable diameter section with variable cross-sectional area; if the cross-sectional areas are different, the variable diameter joints with the changed cross-sectional areas are needed to be in transition connection.

Referring to fig. 1, the relative positions in fig. 1 are shown, in this embodiment, the number of the first reducing joints 110 is one, and the first reducing joints 110, the second boom 150 and the first connecting boom 20 are sequentially arranged at the upper end of the first boom 140 along a preset linear direction from bottom to top; at this time, the lower end of the first arm support 140 is connected to the second connecting arm support 21, directly or indirectly. The second boom 150 is connected between the first boom 140 and the first connecting boom 20, so that the width of the truss arm 100 is gradually reduced from the first boom 140 to the first connecting boom 20, and the width is prevented from changing suddenly, thereby effectively enhancing the overall strength and rigidity of the truss arm 100. Similarly, the number of the first variable diameter joints 110 may be one, and the upper end of the first arm rest 140 is connected to the first connecting arm rest 20, directly or indirectly.

With continued reference to fig. 1, in this embodiment, the truss arm 100 further includes a second reducer joint 120; the end of the second arm support 150 away from the first reducer section 110 is connected to the second reducer section 120. In this embodiment, the second arm support 150 and the second variable diameter section 120 are both strip-shaped frame structures.

There are several situations: to introduce the relative positions in fig. 1, a second boom 150 is disposed at the upper end of the first boom 140, and the first reducing joint 110, the second boom 150, the second reducing joint 120, and the first connecting boom 20 are sequentially disposed at the upper end of the first boom 140 from bottom to top along a preset linear direction; at this time, the lower end of the first arm support 140 is connected to the second connecting arm support 21, directly or indirectly.

With reference to fig. 1, the relative positions in fig. 1 are used for description, in this embodiment, one end of the second variable diameter section 120, which is away from the second boom 150, is used for connecting with the first connecting boom 20, and the first boom 140, the first variable diameter section 110, the second boom 150, the second variable diameter section 120, and the first connecting boom 20 are sequentially connected along a preset straight line. That is, the upper end of the first boom 140 is connected to the second boom 150, and the upper end of the first boom 140 is sequentially connected to the first reducer section 110, the second boom 150, the second reducer section 120, and the first connecting boom 20 from bottom to top along the preset linear direction.

With continued reference to fig. 1, in this embodiment, the truss arm 100 further includes a third reducer section 130; the third reducer 130 is connected to the same ends of the at least two sub-arm supports 141, the third reducer 130 and the first reducer 110 are respectively located at two opposite ends of the first arm support 140, and an end of the third reducer 130 away from the first arm support 140 is used for connecting the second connecting arm support 21. To illustrate the relative position in fig. 1, the first reducer section 110 is connected to the upper end of the first arm rest 140, and the third reducer section 130 is connected to the lower end of the first arm rest 140. The cross-sectional areas of the lower end of the first reducer section 110 and the upper end of the third reducer section 130 are the same, and both are connected to the first arm rest 140. The cross-sectional areas of the upper end of the first variable diameter joint 110 and the lower end of the third variable diameter joint 130 are related to the connection structure of the end of the first variable diameter joint 110 far away from the first arm rest 140 and the end of the third variable diameter joint 130 far away from the first arm rest 140, and when the connection structure of the upper end of the first variable diameter joint 110 and the lower end of the third variable diameter joint 130 is the same, the cross-sectional areas are equal, and when the connection structure of the upper end of the first variable diameter joint 110 and the lower end of the third variable diameter joint 130 is different, the cross-sectional areas are different.

With reference to fig. 1, in this embodiment, the connection structures of the upper end of the first reducer section 110 and the lower end of the third reducer section 130 are different, the upper end of the first reducer section 110 is connected to the second arm support 150, the lower end of the third reducer section 130 is connected to the second connecting arm support 21, and the cross-sectional area of the second arm support 150 is larger than that of the second connecting arm support 21, so that the cross-sectional area of the upper end of the first reducer section 110 is larger than that of the lower end of the third reducer section 130. Specifically, the first arm rest 140, the third reducer section 130, and the second connecting arm rest 21 are sequentially connected from top to bottom along the preset straight line.

With continued reference to fig. 1, in the present embodiment, along the length direction (i.e., the predetermined straight direction) of the truss arm 100, the length of the first reducer 110 and the length of the third reducer 130 are both smaller than the length of the second reducer 120. That is, the length of the first variable diameter section 110 is smaller than the length of the second variable diameter section 120, and the length of the third variable diameter section 130 is smaller than the length of the second variable diameter section 120. In this embodiment, the length of the first variable diameter section 110 is equal to the length of the third variable diameter section 130.

Referring to fig. 1, the number of the sub-arm supports 141 is two, the two sub-arm supports 141 are arranged side by side and have a gap, and the width of the gap is greater than zero and smaller than the width of a single sub-arm support 141. Specifically, the gap ranges from 100mm to 300 mm.

Referring to fig. 1, in the present embodiment, the cross-sectional area of the sub-arm 141, the cross-sectional area of the first connecting arm 20, and the cross-sectional area of the second connecting arm 21 are the same. The sub-boom 141, the first connecting boom 20, and the second connecting boom 21 employ a conventional main boom part. The sub-arm support 141 adopts a conventional main arm part, and two conventional main arm parts are directly arranged side by side without rotating angles and then arranged side by side.

Referring to fig. 2, in conjunction with fig. 3, specifically, the first reducer section 110 is a welded structure. The arm frame joint is welded at two ends of the first reducing joint 110 in a welding mode. The first reducer section 110 is connected to other components through a boom joint in a hinged manner, and specifically, the pin 200 passes through the boom joint to realize connection. The third variable diameter section 130 has the same structure as the first variable diameter section 110, and includes a first end having a larger cross-sectional area and a second end having a smaller cross-sectional area, wherein the first end of the third variable diameter section 130 has the same cross-sectional area as the first end of the first variable diameter section 110 and is connected to the first arm rest 140. The cross-sectional area of the second end of the third variable diameter section 130 is smaller than the cross-sectional area of the second end of the first variable diameter section 110, the second end of the third variable diameter section 130 is connected with the second connecting arm support 21, and the second end of the first variable diameter section 110 is connected with the second arm support 150.

Referring to fig. 3, specifically, the first boom 140 is disposed between the first reducing joint 110 and the third reducing joint 130, the two sub-booms 141 are both conventional main boom components, the upper end of the first boom 140 is connected to the second boom 150 through the first reducing joint 110, the second boom 150 is a reinforcing boom, and the cross-sectional area of the second boom 150 is greater than that of the sub-boom 141; the lower end of the first arm support 140 is connected with the second connecting arm support 21 through a third reducer joint 130. The sub-boom 141 and the second boom 150 are both commercially available, that is, a customer only needs to purchase the first reducer section 110 and the third reducer section 130, so that the truss arm 100 with an increased width can be assembled by assembling the existing sub-boom 141 (conventional main arm component) and the second boom 150 (reinforced arm), thereby improving the suspension capacity of the truss arm 100.

The cross-sectional area of the second arm support 150 is larger than that of the sub-arm support 141. The cross sections of the second arm support 150 and the sub-arm support 141 are rectangular, and each of the cross sections includes a long side and a short side, and the cross section area of the second arm support 150 is larger than the cross section area of the sub-arm support 141, including the long side of the second arm support 150 is larger than the long side of the sub-arm support 141, or the short side of the second arm support 150 is larger than the short side of the sub-arm support 141, or both the long side and the short side of the second arm support 150 are larger than the long side and.

With continued reference to fig. 3, in particular, the first reducer section 110 is hinged to the sub-boom 141 through a pin 200. The first reducer section 110 and the second arm support 150 are also hinged through a pin 200. The second connecting arm support 21 is hinged with the rotary table part of the crane, and the connecting piece is a pin shaft 200.

Referring to fig. 4, two ends of the sub-arm 141 are respectively provided with 4 arm joints, that is, two ends are respectively provided with 4 hinge points to connect with other arm. The sub-arm support 141 may be directly connected to the second connecting arm support 21 by a pin 200. The sub-arm support 141 and the second connecting arm support 21 are hinged in a first plane, the first plane is perpendicular to the preset linear direction, the cross section of the second connecting arm support 21 and the sub-arm support 141 in the first plane is called a first cross section, and the first cross section is a rectangular cross section with a long side and a short side. The first cross section of the second connecting arm frame 21 has the same long side and short side as the sub-arm frame 141.

With continued reference to fig. 4, the second connecting arm support 21 is a variable cross-section arm support assembly, and one end of the second connecting arm support 21 has 4 arm support joints, and is connected to other arm supports (such as the sub-arm support 141) through 4 arm support joints, i.e., 4 hinge points; the other end is provided with 2 hinge points and is connected with a turntable of the crawler crane through the 2 hinge points.

With continued reference to fig. 4, the sub-arm frame 141 may be hingedly connected to the arm head member 10 directly by a pin 200. The sub arm support 141 is hinged to the arm head part 10 in a second plane perpendicular to the preset linear direction, a cross section of the arm head part 10 and the sub arm support 141 at the second plane is called a second cross section, the second cross section is a rectangular cross section having long sides and short sides, and the first cross section of the arm head part 10 and the sub arm support 141 have the same long sides and short sides.

Two ends of the second arm support 150 are respectively provided with 4 arm support joints, namely two ends are respectively provided with 4 hinge points to be connected with other arm supports. The cross-sectional area of the second arm support 150 is larger than that of the sub-arm support 141 and is also larger than that of the first connection arm support 20. That is, the cross-sectional area of the second arm support 150 is larger, and the second arm support 150 cannot be directly hinged to the first arm support 140 and the second connecting arm support 21 through the arm support joint and the pin 200.

Referring to fig. 5, a fixed pulley block is installed, and a wire rope of the hoisting mechanism may be connected to a movable pulley block of the hook through the fixed pulley block of the arm head part 10 to generate a load lifting effect. The number of the hoisting mechanisms can be one or two.

Referring to fig. 6, the sub-boom 141 (a conventional main boom part) may be directly connected to the second connecting boom 21 and the boom head part 10 by means of a hinge pin 200, and the cross section of the second boom 150 is larger than that of the sub-boom 141, and due to the difference in cross section, the second boom 150 cannot be directly connected to the second connecting boom 21 or the boom head part 10.

With continued reference to fig. 6, the second arm support 150 may not be directly connected to the arm head part 10, but must be connected to the first connecting arm support 20 (i.e., a conventional main arm) through another variable diameter joint part (e.g., the second variable diameter joint 120) and connected to the arm head part by the first connecting arm support 20.

The first connecting arm frame 20 (conventional main arm) may be directly connected to the arm head part 10, or other existing variable diameter joint parts and other truss parts having a smaller cross section than the first connecting arm frame 20, that is, other truss arm 100 parts already owned by other customers, such as a light arm or an auxiliary arm part, may be added to the first connecting arm frame 20 and the arm head part 10.

With reference to fig. 6, the number and the length of the sub-arm supports 141 may be selected according to requirements, and the number and the length of the second arm supports 150 may also be selected according to requirements.

The truss arm 100 provided by the embodiment has at least the following advantages:

compared with the arrangement of only one sub-arm support 141, the arrangement of at least two sub-arm supports 141 can increase the overall width of the truss arm 100, so that the lateral load resistance of the arm support can be improved; the second arm support 150 is arranged, so that the width from the first arm support 140 to the two ends of the truss arm 100 is gradually reduced, and the influence of the sudden change of the width on the overall strength and rigidity of the truss arm 100 is avoided, so that the strength, rigidity and lateral load resistance of the truss arm 100 can be improved when the width of the truss arm 100 is increased, and the overall hoisting capacity of the truss arm is effectively improved.

A crane user only needs to purchase the first variable diameter section 110 and the third variable diameter section 130, and can increase the local section width of the truss arm 100 by using the existing first boom 140, the second boom 150 and the second variable diameter section 120 without additionally purchasing a large number of booms or replacing a crane host, thereby improving the hoisting capacity of the boom.

The connection mode between each part of truss arm 100 is articulated, makes things convenient for the on-the-spot installation of hoist and mount and dismantles the transportation.

The above description is only for the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

Claims

1. A truss arm for connecting between a first connecting boom (20) and a second connecting boom (21), the first connecting boom (20) for directly connecting with a boom head member (10), the second connecting boom (21) for directly connecting with a crane turret, comprising:

the cantilever crane comprises a first cantilever crane (140), a first reducer section (110) and a second cantilever crane (150) which are sequentially arranged along a preset linear direction, wherein the cross sectional area of the second cantilever crane (150) is smaller than that of the first cantilever crane (140) and larger than that of a first connecting cantilever crane (20) and that of a second connecting cantilever crane (21);

the first arm support (140) comprises at least two sub-arm supports (141), the at least two sub-arm supports (141) are arranged side by side, the first reducer section (110) is connected with the same end of the at least two sub-arm supports (141), and one end, far away from the first arm support (140), of the first reducer section (110) is connected with the second arm support (150).

2. The truss arm of claim 1 wherein:

the truss arm further comprises a third reducer section (130);

the third variable-diameter joint (130) is connected with the same end of the at least two sub-arm supports (141), the third variable-diameter joint (130) and the first variable-diameter joint (110) are respectively located at two opposite ends of the first arm support (140), and one end, far away from the first arm support (140), of the third variable-diameter joint (130) is used for being connected with the second connecting arm support (21).

3. The truss arm of claim 2 wherein:

the cross-sectional area of the sub-arm support (141), the cross-sectional area of the first connecting arm support (20) and the cross-sectional area of the second connecting arm support (21) are the same.

4. The truss arm of claim 3, wherein:

the number of the sub-arm supports (141) is two, the two sub-arm supports (141) are arranged side by side and are provided with gaps, and the width of each gap is larger than zero and smaller than that of each single sub-arm support (141).

5. The truss arm of any of claims 2-4, wherein:

the truss arm further comprises a second reducer section (120);

one end, far away from the first diameter-changing section (110), of the second arm support (150) is connected with the second diameter-changing section (120).

6. The truss arm of claim 5, wherein:

one end, far away from the second arm support (150), of the second variable-diameter section (120) is used for being connected with the first connecting arm support (20), and the first arm support (140), the first variable-diameter section (110), the second arm support (150), the second variable-diameter section (120) and the first connecting arm support (20) are sequentially connected along the preset straight line.

7. The truss arm of claim 2 wherein:

the first arm support (140), the third reducer section (130) and the second connecting arm support (21) are sequentially connected along the preset straight line.

8. The truss arm of claim 5, wherein:

the length of the first variable diameter section (110) and the length of the third variable diameter section (130) are both smaller than the length of the second variable diameter section (120) along the length direction of the truss arm.

9. The truss arm of claim 5, wherein:

the second arm support (150) and the second variable-diameter section (120) are both strip-shaped frame structures.

10. A crane, characterized by:

the crane comprising a truss arm as defined in any one of claims 1 to 9.